casting numbers

i hope i can get some help on an engine i have disassembled this weekend.
i pulled a 400 apart. the guy i purchased it from bought it and was told it was a 440 but it is a 400 hundered. anyway i stripped it down because i want to build a low deck 512 for my dart. these are the casting numbers i got.

connecting rod 1737682 cant find this in any of my books
S3049 on other side of rod. looks like a stock rod

piston 405np can't find either. rings are high on the piston. 0.268in from top of piston.

crank 3751889 and in my book 74, 2 bbl, cast crank, 440.

this motor came apart way to easy and no marking or scratches on bearings or crank. no ring ridge in the cylinders. ant input will help thanks.